Re: reverse strpos?

am  Mon, dem 12.11.2007, um  8:48:29 -0800 mailte David Fetter folgendes:
> > > Is there a function that?ll return the position of the last
> > > occurance of a char in a string?
> > >
> >
> > write a function to revert the string and use strpos().
> >
> > create or replace function rev(varchar) returns varchar as $$
> > declare
> > ...
> > $$ language plpgsql immutable;
> >
> >
> > Andreas
>
> PL/Perl might be easier:
>
> CREATE OR REPLACE FUNCTION rev(TEXT)
> RETURNS TEXT
> IMMUTABLE
> LANGUAGE plperl
> AS $$
> return reverse($_[0]);
> $$;

heh, the PERL-Guru ;-)


>
> CREATE OR REPLACE FUNCTION rev(TEXT)
> RETURNS TEXT
> IMMUTABLE
> LANGUAGE SQL
> AS $$
> SELECT array_to_string(
>     ARRAY(
>         SELECT substr($1,i,1)
>         FROM generate_series(length($1),1,-1) AS i
>     ),
>     ''
> );
> $$;

Nice.

The generate_series()-function are really great.


Andreas
--
Andreas Kretschmer
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